1. Field of the Invention
This invention relates to an original urging device for supporting an original resting on the original supporting carriage of a copying machine, a printing machine or the like. More particularly, the invention relates to an original urging device which is capable of fixedly holding down not only sheet originals but also three-dimensional originals on the original supporting carriage and which may be stationary within a predetermined range of angles to facilitate the handling of the original urging plate during placement of originals.
2. Description of the Prior Art
For example, electrophotographic copying machines or the like have heretofore employed original urging plates for fixing originals to be copied on transparent original supporting carriages such as glass plates or the like. Some of these conventional original urging plates will hereinafter be described by reference to FIGS. 1 to 6.
FIG. 1 of the accompanying drawings is a perspective view showing an original urging device 1 which is of a simple construction. Designated by 2 is a frame supporting a glass plate (not shown) on which an original may rest, and 3 an original urging plate having a sufficient area to cover the whole surface of the glass plate and formed of rubber or similar material. At one end, the urging plate 3 has its opposite side edges secured to a portion of the frame 2 by means of hinges 4. At the other end, the urging plate 3 is provided with a handle 5 which may be raised in the direction of the arrow to permit placement of an original with the handle left in that position. The original urging device as shown in FIG. 1 is very simple in construction and requires only a few parts and thus, a low cost of manufacture. On the other hand, however, such urging device suffers from inconveniences in operability. When an original is to be placed, one must raise the original urging device by gripping the handle in one's right hand while placing the original by using one's left hand. Such use of both hands to effect placement of an original is inconvenient to the operator of the copying machine or the like. Also, the urging plate, which is entirely formed only of a flexible member, compels the operator to resort to his hands to uniformly hold down the urging plate against the glass plate during copying of a book or other three-dimensional original, and also requires the manual forces of the operator himself, thus raising a problem in terms of operability. A device which has overcome the problems peculiar to the original urging device as shown in FIG. 1 is shown in FIGS. 2 to 4.
FIG. 2 is a perspective view of the urging device, FIG. 3 is a transverse sectional view taken along the center of the FIG. 2 device, and FIG. 4 is an enlarged, fragmentary, cross-sectional view of the mounting portion of the FIG. 2 device. In the original urging device 6 of FIG. 2, a frame 7 supports an original supporting glass plate (not shown) in the center portion thereof. An original urging plate 8 has one end thereof secured to a portion of the frame 7 by means of hinges 9 (See FIGS. 3 and 4), and is pivotable about the hinges 9. Supporting rods 11 extend from a block 10 integrally formed with the urging plate 8, and each rod 11 has one end loosely embedded in a handle 12 secured to the other side edge of the urging plate 8.
Reference will now be had to FIGS. 3 and 4 to describe the manner in which an original is urged. The original urging plate 8, which has one end thereof pivotally secured to the frame 7 by means of hinges 9, as mentioned above, may be raised in the direction of the full-line arrow by gripping the handle 12. When opened beyond 90.degree., the urging plate 8 tends to fall from gravity in the opposite direction, but the back 13 of the block 10 bears against the upper surface of the frame 7 to restrict any further rotation of the plate 8 and enables the plate 8 to remain in that position (indicated by dot-and-dash line) even if the handle 12 is released. In such position, the operator may use both hands to place an original on a glass plate 14. When having placed the original, the operator may again grip the handle 12 to return the urging plate in the direction of the broken-line arrow, thus completing the placement of the original. In the urging device now under discussion, the supporting rods 11 tend to maintain the urging plate 8 horizontal so that the plate 8 can uniformly hold down the original. Further, during the copying of a three-dimensional original, which may be even a thick book 15 as shown in FIG. 4, the urging plate 8 may bend in the form of " " so that the book 15 can be urged against the glass plate 14. In the urging device of FIG. 2, as described above, the urging plate 8 remains open and stationary, so that the operator can use both hands for placement of an original, and this means greater ease of operation than the urging plate of the type shown in FIG. 1. However, depending on the expense of the urging plate 8, it would be impossible for some operators when operating the urging plate 8, to reach the handle 12 to raise it until the stationary position of the urging plate 8 is reached. Also, the urging plate 8 cannot be made stationary unless it is raised always beyond 90.degree., and such poor operability would offer problems.
Another example of the original urging device similar to that of FIG. 2 will be considered by reference to FIGS. 5 and 6. FIG. 5 is a perspective view of the urging device 16, and FIG. 6 is an enlarged, fragmentary sectional view of the mounting portion thereof with respect to the apparatus. In FIG. 5, an original urging plate 17 formed of non-flexible material has one end thereof pivotally secured to the apparatus body by means of hinges 18, and has the other end provided with a handle 19. Placement of an original by this urging device 16 may be accomplished by gripping and raising the handle 19 of the urging plate 27 in the direction of the arrow, as shown in FIG. 6. If the urging plate 17 is located beyond 90.degree., it tends to fall from gravity in the opposite direction from a glass plate 20 as in the previously described urging device, but the back 21 of the urging plate bears against the side wall of the apparatus body and the plate becomes stationary in this position. In such position, an original may be placed on the glass plate 20, and then the urging plate 17 may be returned to its initial position, whereupon the original may be urged against the glass plate by a cushion member 23 provided inwardly of the urging plate 17. The cushion member 23 is formed of porous material such as foamed urethane or the like and thus, slightly thick originals may be placed on this urging plate, although the thickness of the originals is in a limited range. Again in the urging device 16, the urging plate 17 cannot be made stationary unless it is raised always beyond 90.degree., and this poor operability offers problems.
Also known is an original urging device disclosed in our previous U.S. Pat. No. 3,994,582. In this device, the urging plate can be maintained open at an angle within 90.degree., but this is only possible within a predetermined angle. Thus, even for this device, the urging plate must be opened to the predetermined angle and this involves an extra operation. In addition, the height of the operator is not taken into account and the necessity of raising the urging plate to the predetermined angle also offers problems in operabitlity.